Bioburden-reducing fabrics and methods

ABSTRACT

Bioburden reducing fabrics include a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof. A surface of the fabric, when exposed to a pathogenic environment for twenty hours, allows no more than a total average of about twenty-two CFUs of pathogens per square centimeter to be formed thereon.

RELATED APPLICATION

This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/469,449 filed Mar. 30, 2011, the disclosure of which is incorporated herein by reference as if set forth in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to bioburden and, more particularly, to methods of reducing bioburden.

BACKGROUND

Nosocomial infections are infections that are a result of treatment in a medical facility, such as a hospital. Nosocomial infections typically affect patients who are immunocompromised because of age, underlying diseases, or medical or surgical treatments. Pathogenic microorganisms that cause the most nosocomial infections usually come from the patient's own body (endogenous flora), from contact with staff (cross-contamination), from contact with contaminated instruments and needles, and from the environment (exogenous flora). Medical facilities typically have sanitation protocols regarding uniforms, equipment sterilization, washing, and other measures for preventing the occurrence of infections. Despite sanitation protocols, nosocomial infections remain a serious problem in hospitals and other medical facilities.

SUMMARY

It should be appreciated that this Summary is provided to introduce a selection of concepts in a simplified form, the concepts being further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of this disclosure, nor is it intended to limit the scope of the invention.

In view of the above, a bioburden reducing fabric, according to some embodiments of the present invention, comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings. A surface of the fabric, when exposed to a pathogenic environment for twenty (20) hours, allows no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter to be formed thereon. Exemplary pathogens that can be reduced via use of fabrics, according to embodiments of the present invention, include gram negative and gram positive bacterial pathogens.

In some embodiments of the present invention, the fabric includes warp yarns that are about 30 denier to 100 denier, and filling yarns that are about 30 denier to 100 denier. One of the warp or filling yarns is 100% continuous filament nylon having round filament cross sections and makes up at least 40% by weight of the fabric. The other of the warp or filling yarns is continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and makes up the remainder of the weight of the fabric. The fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%. The fabric has zero percent (0%) weight loss after one hundred (100) launderings in accordance with the AATCC 61 test method.

In some embodiments of the present invention, the warp yarns are 100% nylon, such as 70 denier, 48 filament, textured, continuous filament nylon yarns.

In some embodiments of the present invention, the filling yarns are 100% polyester, such as 75 denier, 36 filament, continuous filament textured polyester yarns.

In some embodiments of the present invention, the filling yarns are 100% nylon.

In some embodiments of the present invention, the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels. Exemplary non-round filament cross sections include star shaped cross sections and clover leaf cross sections.

In some embodiments of the present invention, an antimicrobial substance is topically applied to the fabric.

According to other embodiments of the present invention, a method of reducing bioburden within a medical facility includes: (a) fitting essentially all beds within the facility with clean sheets, wherein each sheet comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; (b) occupying the beds with patients, wherein the sheets on average contain no more than an average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a bed occupant; and (c) repeating steps (a)-(b) for a number of times sufficient to reduce the bioburden within the facility.

In some embodiments of the present invention, the sheet fabric includes warp yarns that are about 30 denier to 100 denier, and filling yarns that are about 30 denier to 100 denier. One of the warp or filling yarns is 100% continuous filament nylon having round filament cross sections and makes up at least 40% by weight of the sheet fabric. The other of the warp or filling yarns is continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and makes up the remainder of the weight of the fabric. The sheet fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.

In some embodiments of the present invention, the warp yarns of the sheet fabric are 100% nylon, such as 70 denier, 48 filament, textured, continuous filament nylon yarns.

In some embodiments of the present invention, the filling yarns of the sheet fabric are 100% polyester, such as 75 denier, 36 filament, continuous filament textured polyester yarns.

In some embodiments of the present invention, the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels. Exemplary non-round filament cross sections include star shaped cross sections and clover leaf cross sections.

In some embodiments of the present invention, an antimicrobial substance is topically applied to the sheet fabric.

According to other embodiments of the present invention, a method of reducing bioburden within a medical facility includes: (a) dressing each patient within the facility with a clean hospital gown, wherein each hospital gown comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; (b) maintaining the patients within beds in the facility, wherein the gowns on average contain no more than an average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a patient; and (c) repeating steps (a)-(b) for a number of times sufficient to reduce the bioburden within the facility.

In some embodiments of the present invention, the gown fabric includes warp yarns that are about 30 denier to 200 denier, and filling yarns that are about 30 denier to 200 denier. The warp and filling yarns are continuous filament polyester having round cross sections. The gown fabric has an average Kawabata geometric roughness of less than about 1.2 microns and a percent (%) dryness after 1 hour of 100%.

In some embodiments of the present invention, the warp yarns of the gown fabric are 100% polyester, such as 70 denier, 200 filament, textured, continuous filament polyester yarns.

In some embodiments of the present invention, the filling yarns of the gown fabric are 100% polyester, such as 70 denier, 200 filament, continuous filament textured polyester yarns.

In some embodiments of the present invention, an antimicrobial substance is topically applied to the gown fabric.

According to other embodiments of the present invention, a method of reducing bioburden within a medical facility includes fitting essentially all beds within the facility with clean sheets, wherein each sheet comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; collecting the sheets after twenty (20) hours of use by occupants of the beds; and laundering the collected sheets. A surface of each sheet allows no more than an average of about twenty-five (25) CFUs of pathogens per square centimeter to be formed thereon after at least thirty (30) laundering cycles.

In some embodiments of the present invention, the sheet fabric includes warp yarns that are about 30 denier to 100 denier, and filling yarns that are about 30 denier to 100 denier. One of the warp or filling yarns is 100% continuous filament nylon having round filament cross sections and makes up at least 40% by weight of the sheet fabric. The other of the warp or filling yarns is continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and makes up the remainder of the weight of the fabric. The sheet fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.

In some embodiments of the present invention, the warp yarns of the sheet fabric are 100% nylon, such as 70 denier, 48 filament, textured, continuous filament nylon yarns.

In some embodiments of the present invention, the filling yarns of the sheet fabric are 100% polyester, such as 75 denier, 36 filament, continuous filament textured polyester yarns.

In some embodiments of the present invention, the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels. Exemplary non-round filament cross sections include star shaped cross sections and clover leaf cross sections.

In some embodiments of the present invention, an antimicrobial substance is topically applied to the sheet fabric.

According to other embodiments of the present invention, a non-treated fabric comprises warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof. The warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier. One of the warp or filling yarns is 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric. The other of the warp or filling yarns is continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric. The fabric has zero percent (0%) weight loss after one hundred (100) launderings in accordance with the AATCC 61 test method.

In some embodiments of the present invention, the warp yarns of the non-treated fabric are 100% nylon, such as 70 denier, 48 filament, textured, continuous filament nylon yarns.

In some embodiments of the present invention, the filling yarns of the non-treated fabric are 100% polyester, such as 75 denier, 36 filament, continuous filament textured polyester yarns.

In some embodiments of the present invention, the continuous filament warp or filling yarns with non-round filament cross sections of the non-treated fabric are configured such that adjacent filaments form wicking channels. Exemplary non-round filament cross sections include star shaped cross sections and clover leaf cross sections.

Fabrics manufactured according to embodiments of the present invention can reduce bioburden within a medical facility (e.g., a medical facility maintained at a temperature of between about 60° F. (15° C.) and 80° F. (27° C.) and at a humidity level of between about 35% relative humidity and about 55% relative humidity) by at least half (50%) on beds in the medical facility that are occupied by human patients when the sheets are changed at least every two days (e.g., 24-48 hours).

Fabrics according to embodiments of the present invention can be utilized to manufacture various articles utilized in medical facilities and are not limited to the manufacture of sheets (i.e., bottom sheets and top sheets) and hospital gowns. For example, fabrics according to embodiments of the present invention can be utilized to manufacture pillow cases, underpads, masks, cubicle, surgical caps, uniforms, etc.

It is noted that aspects of the invention described with respect to one embodiment may be incorporated in a different embodiment although not specifically described relative thereto. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination. Applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to be able to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner. These and other objects and/or aspects of the present invention are explained in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which form a part of the specification, illustrate some exemplary embodiments. The drawings and description together serve to fully explain the exemplary embodiments.

FIG. 1 is an illustration of an exemplary bed covered with sheet(s) according to some embodiments of the present invention, and exemplary pillows covered with pillowcases according to some embodiments of the present invention.

FIG. 2 is a photomicrograph of a yarn with filaments having star-shaped fiber cross sections according to some embodiments of the present invention.

FIG. 3 is a photomicrograph of a yarn with filaments having cloverleaf-shaped fiber cross sections according to some embodiments of the present invention.

FIGS. 4 and 5 are graphs illustrating a bioburden analysis comparing fabric, according to some embodiments of the present invention, with conventional cotton-blend hospital bedding and patient gowns, in their laundered state (FIG. 4) and after patient use (FIG. 5).

FIG. 6 is a graph of a comparison of particle and lint generation between fabric according to some embodiments of the present invention and conventional cotton-blend hospital top and bottom sheets.

FIG. 7A is a photomicrograph of an unlaundered fabric according to some embodiments of the present invention.

FIG. 7B is a photomicrograph of the fabric of FIG. 7A after being laundered one hundred seventy five (175) times.

FIG. 8A is a photomicrograph of an unlaundered conventional cotton/polyester hospital bedding fabric.

FIG. 8B is a photomicrograph of the cotton/polyester fabric of FIG. 8A after being laundered one hundred seventy five (175) times.

FIG. 9 is a graph illustrating fiber loss for a fabric according to some embodiments of the present invention and for a standard polyester/cotton fabric currently used in hospital sheets after extended laundering.

FIG. 10 is a table illustrating bioburden reduction by an untreated fabric, according to some embodiments of the present invention.

DETAILED DESCRIPTION

The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which some embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element, or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of embodiments of the present invention in use or operation in addition to orientations depicted in the figures. For example, if an illustrated embodiment in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of “over” and “under”. The embodiment may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

The term “medical facility”, as used herein, refers to any location at which health care is provided to patients and includes, but is not limited to, hospitals, clinics, and the like.

The term “pathogen”, as used herein, refers to any infectious biological agent such as a virus, bacteria, prion, or fungus that may cause disease to its host. Bacterial pathogens include “gram negative” and “gram positive” bacterial pathogens. Exemplary gram negative and gram positive pathogens include, but are not limited to: Acidovorax delafieldii, Acinetobacter baumannii, Actinomycete, Bacillus cereus, Bacillus circulans, Bacillus licheniformis, Bacillus sphaericus, Brevundimonas diminuta, Corynebacterium coyleae, Corynebacterium sp., Enterococcus casseliflavus, Enterococcus faecalis, Enterococcus gallinarum, Enterococcus sp., Gram positive bacillus, Gram positive cocci, Gram positive rod, Klebsiella sp., Lactococcus lactis, Microbacterium aurantiacum, Micrococcus luteus, Micrococcus sp., Micrococcus lylae, Nocardia farcinica, Pseudomonas putida, Pseudomonas oryzihabitans, Rhizobium radiobacter, Staphylococcus aureus, Staphylococcus cohnii, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus pasteuri, Staphylococcus sp. (non-aureus), and Staphylococcus xylosus.

The term “pathogen environment”, as used herein, refers to any environment in which exposure to pathogens is possible.

The term “bioburden”, as used herein, refers to the number of pathogens with which an object is contaminated. The degree of bioburden may be measured by counting the number of colony-forming units (CFUs). A CFU is a measure of viable bacterial or fungal numbers, and may be reported as CFU/mL (colony-forming units per milliliter) for liquids, and CFU/g (colony-forming units per gram) for solids.

The term “bioburden within a medical facility”, as used herein, refers to bioburden as detected on one or more objects within that facility, particularly objects that contact a patient such as patient beds or sheets fitted thereon.

The term “bed”, as used herein, refers to any device or apparatus upon which or within which a patient sleeps, rests, or stays when in a medical facility.

The term “fitting”, as used herein with respect to beds, refers to making a bed with a sheet that conforms to the shape of a mattress or other patient support surface (i.e., a bottom sheet). Also, top sheets may be fitted to a bed.

The term “clean”, as used herein, refers to a fabric that has been laundered.

The terms “filament” and “fiber”, as used herein, are interchangeable. Yarns utilized in producing fabrics according to embodiments of the present invention are formed from a plurality of continuous filaments/fibers.

The term “non-treated woven fabric”, as used herein, refers to a woven fabric that has not been treated with an antimicrobial substance.

Fabric, according to embodiments of the present invention, may have various uses including, but not limited to, bedding, blankets, pillow encasements, underpads, mattress encasements, gowns, bandages for wound care, curtains and draperies, patient moving/lifting devices, patient support systems, wheel chair covers and encasements, booties, sleep sacks, etc. A fabric, according to embodiments of the present invention is formed with a woven fabric having warp yarns and filling yarns woven to provide an identically smooth fabric surface on both sides thereof. In some embodiments of the present invention, one of the warp or filling yarns is at least 40% by weight of the fabric of continuous filament nylon. For example, one of the warp or filling yarns is at least 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%, by weight of the fabric of continuous filament nylon. The other of the warp or filling yarns is greater than 0% by weight of the fabric and up to about to 60% by weight of the fabric of continuous filament polyester or nylon having non-round filament cross sections. For example, the other of the warp or filling yarns may be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60% by weight of the fabric of continuous filament polyester or nylon having non-round filament cross sections.

In some embodiments of the present invention, an antimicrobial substance is topically applied or inherently available in the fabric. In some embodiments, an antimicrobial substance such as AEGIS Microbe Shield, manufactured by W.M. Barr & Co. (Memphis, Tenn.), is topically applied to the woven fabric in a standard textile finishing operation. This antimicrobial is effective against the following common microbes: Escherichia Coli, Staphylococcus Aureus, Staphylococcus Epidermidis, Pseudomonas Aeruginosa. The antimicrobial substance may also prevent odors in the fabric.

In some embodiments, the warp yarns may be 100% nylon, and the filling yarns may be polyester or nylon.

In one embodiment, the fabric is woven as a twill weave (typically a 2×1 twill) or plain weave. Yarns are woven into fabric constructions that have 80% to 100% coverage. The warp yarn may be, for example, a 40 denier, 34 filament, five twist per inch, continuous filament nylon 6-6 yarn, and the filling yarn may be a 75 denier, 48 filament, continuous filament textured polyester. In another embodiment, the warp yarn is, for example, a 70 denier, 48 filament, continuous filament, textured nylon, and the filling yarn is, for example, a 75 denier, 36 filament, continuous filament, textured polyester. However, embodiments of the present invention are not limited to these examples. Yarns with various different fiber densities and filament numbers may be utilized.

Continuous filament yarns are utilized because those yarns do not have short fibers extending beyond the fabric's planar surface, thereby decreasing irritation to sensitive skin. Also, fibers extending beyond a fabric's planar surface, as found in cotton-blend hospital fabrics, can loosen, shed or break off and thereby contribute bioburden to the patient's environment in the form of contaminated fiber particles. These fiber particles can then contaminate open wounds or be inhaled or ingested by patients, caretakers, and housekeeping staff. This difference is readily seen in FIG. 6, where the relative particle and lint generation of fabric according to embodiments of the present invention and cotton-blend hospital linens are measured and compared. The data shown in FIG. 6 indicates reductions in particle generation of 98.7% when the present invention is compared with cotton fitted sheets and 97.0% when compared with cotton top sheets. Thus, the smooth, identical surfaces of fabric according to embodiments of the present invention mitigate the potential for bioburden contamination. In other embodiments of the present invention, warp yarns of about 30 denier to 100 denier, and filling yarns of about 30 denier to 100 denier may be used. For example, warp and filling yarns may have any mass density within the range of 30 denier to 100 denier (e.g., 31 denier, 32 denier, 33 denier, 34 denier, 35 denier, 36 denier, 37 denier, 38 denier, 39 denier, 40 denier, 41 denier, 42 denier, 43 denier, 44 denier, 45 denier, 46 denier, 47 denier, 48 denier, 49 denier, 50 denier, 51 denier, 52 denier, 53 denier, 54 denier, 55 denier, 56 denier, 57 denier, 58 denier, 59 denier, 60 denier, 61 denier, 62 denier, 63 denier, 64 denier, 65 denier, 66 denier, 67 denier, 68 denier, 69 denier, 70 denier, 71 denier, 72 denier, 73 denier, 74 denier, 75 denier, 76 denier, 77 denier, 78 denier, 79 denier, 80 denier, 81 denier, 82 denier, 83 denier, 84 denier, 85 denier, 86 denier, 87 denier, 88 denier, 89 denier, 90 denier, 91 denier, 92 denier, 93 denier, 94 denier, 95 denier, 96 denier, 97 denier, 98 denier, or 99 denier).

In some embodiments, the continuous filaments have non-round fiber cross-sections such as, for example, star shaped cross sections or clover leaf cross sections. A clover-leaf cross section also improves the fabric's smoothness and softness. Examples of these non-round fiber cross sections are seen in FIGS. 2 and 3. With non-round fiber cross sections, adjacent filaments form wicking channels along fiber surfaces to promote and enhance moisture transport away from contact with the skin. Thus, moisture more quickly evaporates and dries away from the fabric surface, reducing the amount of moisture contacting the skin. The capillary action of fabrics according to embodiments of the present invention further serves to cause die-off of bacteria on the fabric. Moisture wicking reduces the overall moisture in the fabric which, therefore, helps dry out the bacterial cells on the fabric, causing them to more readily die off.

In some embodiments, nylon is used because it has one of the highest moisture regains of any synthetic fiber. Nylon absorbs moisture, and aids in wicking and evaporation. Polyester can also be used, according to some embodiments of the present invention, particularly if a durable auxiliary hydrophilic treatment is applied as a post finish.

In some embodiments, the fabric may also contain a soil-release topical finish. Thus, the fabric is able to release stains associated with skin antibiotic creams and ointments, as well as other stain-causing agents.

As seen in FIG. 1, a sheet 10 (i.e., a bottom sheet and/or a top sheet) fitted to a bed is made with a woven fabric having warp yarns and filling yarns woven to provide a smooth fabric surface and sized to cover a bed. The sheet(s) 10 may have hems 14 to prevent raveling of the woven fabric. In some embodiments of the present invention, one of the warp or filling yarns is at least 40% by weight of the fabric of continuous filament nylon, and the other of the warp and filling yarns is 60% or less by weight of the fabric of continuous filament polyester or nylon having non-round filament cross sections. In some embodiments of the present invention, all of the filaments in the yarn have non-round cross sections. An antimicrobial substance may be topically applied or inherently available in the fabric.

Also as seen in FIG. 1, a pillowcase 12 is made with a woven fabric as described above. The pillowcase 12 is sewn to form a pocket to encase a pillow with an opening 16 on one end to enable insertion of a pillow therein. One of the warp or filling yarns is at least 40% by weight of the fabric of continuous filament nylon, and the other of the warp or filling yarns is 60% or less by weight of the fabric of continuous filament polyester or nylon having non-round filament cross sections. In some embodiments of the present invention, an antimicrobial substance is topically applied or inherently available in the fabric.

Fabrics according to embodiments of the present invention have high moisture regain and excellent moisture transport. Nylon, with one of the highest moisture regains of any synthetic fiber, absorbs moisture and aids in wicking and evaporation. Non-round filament cross sections create channels along filament surfaces to promote and enhance moisture transport away from contact with the skin. Moisture more quickly evaporates and dries, and thereby reduces the amount of wetness next to the skin. As such, fabrics according to embodiments of the present invention help a patient or other user maintain body temperature by reducing excess sweating. In some embodiments of the present invention, the fabric is 100% dry after 1 hour. As discussed above, the capillary action helps cause die-off of bacteria on the fabric. Moisture wicking reduces the overall moisture in the fabric, which therefore helps dry out the bacterial cells, causing them to more readily die off.

Fabrics according to embodiments of the present invention have minimal friction with the skin of a patient. Continuous-filament yarns have no short fibers extending beyond the fabric's planar surface to irritate sensitive skin. A smooth fabric surface accentuates this effect. In some embodiments of the present invention, the fabric has an average geometric roughness of less than about 1.7 microns as measured by the Kawabata Evaluation System FB4 Surface Tester.

Fabrics according to embodiments of the present invention have a good degree of stretch and recovery. Such fabrics help bed sheets to fit tighter and thereby reduce wrinkling that can cause skin irritation. Such fabrics also better conform to the body and reduce shear forces on sensitive skin. In some embodiments of the present invention, the fabric is finished to produce a fabric with an elongation greater than about 30% as measured by ASTM D5034-95.

Fabrics according to embodiments of the present invention have durability to extended laundering and drying. Fabrics, according to embodiments of the present invention, will not lose fibers during laundering (in comparison with cotton blends), and are not afflicted with fiber pills that further irritate skin. For example, FIG. 7A is a photomicrograph of a fabric according to some embodiments of the present invention. FIG. 7B is a photomicrograph of the fabric of FIG. 7A after being laundered one hundred seventy five (175) times. FIG. 7B demonstrates that fabric according to embodiments of the present invention is unaffected by extended laundering, even after one hundred seventy five (175) actual wash/dry cycles under hospital-laundry conditions.

In contrast, FIG. 8A is a photomicrograph of a conventional cotton/polyester hospital bedding fabric. The surface of the fabric in FIG. 8A is much rougher than the surface of the fabric in FIG. 7A. FIG. 8B is a photomicrograph of the cotton/polyester fabric of FIG. 8A after being laundered one hundred seventy five (175) times. As clearly illustrated, the cotton/polyester fabric is substantially degraded and has a significantly rougher surface as a result of extended laundering. Moreover, conventional hospital cotton/polyester fabrics lose substantial weight and most of their tensile strength during extended laundering.

Fabrics according to embodiments of the present invention are able to withstand high wash temperatures and the use of harsh detergents, and are able to release stains associated with skin antibiotic creams and ointments, as well as other stain-causing agents. Moreover, fabrics according to embodiments of the present invention have antibacterial efficacy against the survival of S. aureus, fungus, and molds on the fabric surface. In some embodiments of the present invention, the fabric has an antimicrobial efficacy against E. Coli, Staph. Epidermidis, and P. Aeruginosa of at least about 99.4% per AATCC 100.

Fabrics according to embodiments of the present invention have resistance to odors.

The data for fabrics woven with the yarns of FIGS. 2 and 3 are compared with conventional 55/45 polyester/cotton and 100% cotton bedding fabrics in Table 1 below.

TABLE 1 Present Invention Conventional Sheets Warp Yarn 40/34 40/34 70/48 55/45 100% 7z Nylon 7z Nylon Textured nylon Poly/cotton Cotton Fill Yarn 75/48 70/72 75/36 55/45 100% Text. Poly. Text. Nylon Text. Poly. Poly/cotton Cotton Fabric Weight osy 2.53 2.51 2.43 3.72 3.44 Yarns per Inch, warp epi 180 173 102 111 113 Yarns per Inch, fill ppi 110 107 104 79 84 Avg. Elongation % 37.6 37.4 39.6 17.2 12.8 Air Permeability cfm/ft² 10.7 9.2 30.5 39.5 39.4 Circular Bend N 0.7 0.6 0.3 0.9 0.7 Thermal Insulation Value Clo 0.49 0.50 n/a 0.53 0.55 Soil Release to Oily Stains 3.0 2.5 5.0 3.5 3.0 Coefficient of Friction, warp 0.53 0.35 0.22 1.10 1.00 Coefficient of Friction, fill 0.50 0.56 0.23 1.08 1.03 Avg. Surface Roughness μ 1.4 1.1 1.5 3.7 2.3 Fabric Dryness after 1 hour % 100% 100% 100% 51% 52%

Fabric according to some embodiments of the present invention, referred to below in Table 2 as DermaTherapy® bedding fabric S/66514, was tested to determine the weight loss when subjected to repeated launderings. A conventional Polyester/Cotton blend hospital sheet was also tested to evaluate for weight loss and was compared with DermaTherapy® S/66514. DermaTherapy® fabric S/66514 and Polyester/Cotton blend hospital sheet samples were cut and weighed—three 2″×6″ samples of each. The test specimens were washed in a Laundrometer using the AATCC 61 test method which mimics several washings in one cycle. For this testing, 5A wash settings were used, that represents 5 washes in one cycle. After the wash cycle, the specimens were transferred to the dryer. After the dryer cycle, the test specimens were reconditioned for 1 hour. The specimens were then weighed and the percent weight loss was calculated using the following calculation:

${\% \mspace{14mu} {Weight}\mspace{14mu} {Loss}} = {\frac{{Original} - {Final}}{Original} \times 100}$

Weight loss results for DermaTherapy® bedding fabric S/66514 and for conventional Polyester/Cotton blend hospital sheet are summarized in Table 2 below.

TABLE 2 DermaTherapy ® Polyester/Cotton Hospital Number of Style/66514 Sheet Launderings Weight Loss % Weight Loss %  1x 0% 1.51%  25X 0% 3.92%  50X 0% 6.25%  75X 0% 7.26% 100X 0% 8.24% As clearly illustrated in Table 2, fabric according to embodiments of the present invention did not lose any fibers as a result of laundering and, thus, had no weight loss. In contrast, the conventional Polyester/Cotton blend hospital sheet exhibited significant weight loss. This is graphically illustrated in FIG. 9, also.

Fabrics according to embodiments of the present invention are capable of retaining antimicrobial substances applied thereto much longer than conventional hospital sheet fabrics. The antimicrobial substance is applied as a surface treatment (not a coating) to the fabrics according to the embodiments, where the active ingredient is molecularly bound to the fiber surfaces. The application process involves processing the fabric through a bath of chemicals, followed by a series of pad/squeeze rolls to remove excess chemicals leaving a precise amount of chemicals on the fabric, and finally through a drying process where the molecular bonding takes place. The inactive ingredient (water) is driven off during the drying process and does not otherwise remain on or in the fabric. After processing, the fabric is clean and free of any chemical residues. The active ingredient in AEGIS forms a colorless, odorless, positively charged polymer that molecularly bonds to the treated surface. It can be thought of as a surface layer of electrically charged swords. When a microorganism comes in contact with the treated surface, the C-18 molecular sword punctures the cell membrane and the positive electrical charge disrupts the cell wall. Since nothing is transferred to the now dead cell, the antimicrobial does not lose strength and the molecule is available for the next cell to contact it. The antimicrobial substance is an “organofunctional silane” with a quaternary ammonium component. The silane component permanently attaches the molecule to the fabric surface. The cured antimicrobial does not volatilize, dissipate, or leach onto other surfaces or into the environment. The chemistry polymerizes where it is applied and forms a permanent bond that typically lasts for the life of the treated surface. Therefore, fabrics according to embodiments of the present invention retain antimicrobial substances applied thereto even after extended laundering.

Actual-Use Testing of Bioburden Reduction

To demonstrate the ability of embodiments of the present invention to reduce bioburden, Applicants obtained bacterial measurements from control cotton-blend bedding fabric (i.e., sheets) and hospital bedding fabric (i.e., sheets) in a hospital setting under actual-use conditions, for example where temperature is maintained within a range of between about 60° F. (15° C.) and 80° F. (27° C.) and humidity level is maintained at a level of between about 35% relative humidity and about 55% relative humidity. Swab samples were taken each week during an eight (8) week control session and an eight (8) week study session, for control and experimental bedding fabrics, using sterile-saline-moistened swabs. In testing the bedding fabrics, bacterial swab samples were taken from the bottom fitted sheet at a point on the sheet which contacts the approximate lower part of a patient's scapula or center of the back; that is, twenty-four inches (24″) from the top of the bed in the center-most part of the bed sheet, on the surface closest to the patient's skin. Swab specimens were taken on fitted sheets received from the laundry on the date of the testing, prior to use, and picked at random; and on fitted sheets which had been used continuously by different patients at least twenty (20) hours prior to sampling, and picked at random. Bedding fabrics were removed from the bed and swabbed in an area remote from patients' rooms. The swab specimens were evaluated by an independent laboratory to quantify the number of CFUs of detectable bacteria per square centimeter present. The results for the bedding fabrics are summarized in Table 3 below. DermaTherapy® brand fabrics represent a fabric according to some embodiments of the present invention and that includes a topical treatment of an antimicrobial substance. Data was analyzed using one-way ANOVA or t-test statistical methods, with the two groups (“Control” and “DermaTherapy”) as the sub-groups. In each case, significant differences are indicated for p-values less than 0.05.

TABLE 3 “Freshly Laundered” Bedding “Used” Bedding Control DermaTherapy ® p value Control DermaTherapy ® p value Average CFUs 11.7 0.0 0.05 1,197.9 22.0 0.04 per CM²

As shown in Table 3, the ability of DermaTherapy® bedding fabric to reduce bacteria on hospital bedding, taken from a hospital laundry prior to use, over an eight (8) week period, was outstanding at an average of 0.0 CFUs/cm² (i.e., no detectable bacteria over an eight (8) week period).

As shown in Table 3, under actual hospital-use conditions over an eight (8) week period, DermaTherapy® bedding fabrics used by patients for twenty to twenty-four (20-24) hours, showed a 98.1% reduction in bioburden, as compared with conventional cotton bedding fabrics. With both laundered and used DermaTherapy® bedding fabrics, the results were statistically significant. As such, fabrics according to embodiments of the present invention reduce bioburden on hospital bedding, and also reduce odors on fabrics caused by germs and bacteria.

Laboratory Testing of Bioburden Reduction

To simulate actual end-use conditions, treated fabrics (i.e., fabrics treated with an antimicrobial substance) according to embodiments of the present invention (DermaTherapy®) were tested in the laboratory per AATCC 100-2004 (“Antibacterial Finishes on Textile Materials: Assessment of”) using Log⁶ CFU/ml challenge inoculums (i.e., the initial pathogen challenge), measuring antimicrobial activity after an eight (8) hour exposure. To assess laundering durability, DermaTherapy® fabric samples were subjected to thirty (30) laundering cycles and then tested per the modified AATCC 100-2004. Two Gram-positive pathogens (Staphylococcus epidermidis and Staphylococcus aureus) and two Gram-negative pathogens (Klebsiella pneumoniae and Escherichia coli) were used in these tests. The results, given below, showed the performance of DermaTherapy® in as-new, unwashed condition (Table 4) and after 30 wash-dry cycles (Table 5). In all cases, greater than a 4-log reduction was observed for these four pathogens after an eight (8) hour exposure.

TABLE 4 Microbiological Analysis AATCC 100 - Modified DermaTherapy ® was tested in as-new condition Log¹⁰ CFU Log¹⁰ CFU Initial after 8-hour Log¹⁰ Test Organisms Concentration contact Reduction Staphylococcus epidermidis 6.04 <1.0 >5.04 Staphylococcus aureus 6.11 <1.0 >5.11 Klebsiella pneumonia 6.38 1.0 5.38 Escherichia coli 6.01 <1.0 >5.01

TABLE 5 Microbiological Analysis AATCC 100 - Modified After DermaTherapy ® was laundered 30X Log¹⁰ CFU Log¹⁰ CFU Initial after 8-hour Log¹⁰ Test Organisms Concentration contact Reduction Staphylococcus epidermidis 6.04 2.0 4.02 Staphylococcus aureus 6.11 <1.0 >5.11 Klebsiella pneumonia 6.38 1.2 5.18 Escherichia coli 6.01 <1.0 >5.01 The results, as indicated above, are excellent, with outstanding durability after laundering. As an example, a “5-log reduction” is equivalent to a 99.999% reduction from the initial challenge. As illustrated in Tables 4 and 5, fabrics according to embodiments of the present invention significantly reduce pathogens thereon, even after being laundered.

The procedures for collecting bacterial swab samples from an actual hospital and the analysis thereof to produce the results illustrated above in Tables 3-5 are set forth below in further detail.

Bioburden Reduction without Anti Microbial Treatment

Applicants unexpectedly have found that fabrics, according to embodiments of the present invention, can substantially reduce bioburden without any anti-microbial treatment applied thereto. To simulate actual end-use conditions, untreated fabrics (i.e., fabrics without the AEGIS antimicrobial application) according to embodiments of the present invention (DermaTherapy®) were tested in the laboratory per AATCC 100-2004 using Log⁶ CFU/ml challenge inoculums (i.e., the initial pathogen challenge), measuring antimicrobial activity after an eight (8) hour exposure. Two Gram-positive pathogens (Staphylococcus epidermidis and Staphylococcus aureus) and two Gram-negative pathogens (Klebsiella pneumoniae and Escherichia coli) were used in these tests. The results are set forth in FIG. 10. The illustrated results are given as CFU/sample and CFU/cm² at “Time Zero” and after “8 Hour Contact”. Die-off on the samples without the antimicrobial agent was observed. Without wishing to be held to any particular theory, Applicants believe that the capillary action of the DermaTherapy® fabric promotes moisture wicking which reduces overall moisture in the sample, which in turn helps dry out the pathogen cells, thereby causing the pathogen cells to die off.

Procedures for Collecting Bacterial Swab Samples and their Analyses

Bacterial contamination measurements were taken to isolate, identify and compare the pathogenic bacteria prevalent on control and experimental bed sheets and patient gowns used in this study. Swab samples of control and experimental bedding and gowns were taken once each week during the eight (8) week duration of the study using sterile-saline-moistened swabs.

In testing the bed sheets, bacterial swab samples were taken from the bottom fitted sheet at a point on the sheet which contacts the approximate lower part of a patient's scapula or center of the back; that is, twenty-four (24) inches from the top of the bed in the center-most part of the bed sheet, on the surface closest to the patient's skin. Swab specimens were taken on five (5) fitted sheets received from the laundry on the date of the testing, prior to use, and picked at random; and on five (5) fitted sheets which have been used continuously by five different patients at least twenty (20) hours prior to sampling, and picked at random. Bed sheets were removed from the bed and swabbed in an area remote from the patients' rooms. Over the course of the trial, one hundred sixty (160) samples were taken from both unsoiled and soiled bed sheets.

At least once per week during the study, blank swab samples were also taken where the individual collecting the swab samples would go through the procedure described above, but did not contact the textile materials at any point with the swab. These blank samples are intended to confirm the sterility of the sample collection process.

In testing the patient gowns, bacterial swab samples were taken from a point on the gown at the approximate base of a patient's sternum; that is, eight (8) inches below the neckline of the center portion of the patient gown, on the inside of the gown. Swab samples were taken on five (5) gowns received from the laundry on the day of the testing, prior to use, and picked at random; and on five (5) gowns which had been used continuously by five different patients at least twenty (20) hours prior to testing, and picked at random. Gowns were removed from the patients and swabbed in an area remote from the patients' rooms. Over the course of the trial, one hundred sixty (160) samples were taken from both the unsoiled and soiled patient gowns.

Bacteria measurements included the quantification and identification of the most common bacteria to the genus and to the species where possible. In the bioburden results illustrated in FIGS. 4 and 5, the average total CFUs of bacteria/cm² per item were measured, revealing a stark contrast with the conventional cotton linens and gowns. DermaTherapy® sheets and gowns were cleaner as delivered from the laundry with reductions in bioburden of 100% (p=0.05) and 91.9% (p=0.16), respectively. After 20-24 hours of use, the DermaTherapy® sheets and gowns reduced the bioburden by 98.1% (p=0.04) and 98.3% (p=0.02), respectively. These results represent significant reductions in bioburden demonstrated by DermaTherapy® fabrics when compared with conventional cotton-blend products when used under actual conditions over a two-month period.

Data was analyzed using one-way ANOVA or t-test statistical methods, with the two groups (experimental and control) as the sub-groups. For all analyses, significant differences are indicated for p-values less than 0.05.

Collection of Swab Specimens

-   -   Samples were collected using aseptic techniques. Sterile swabs         (Fisher Scientific, Catalog #14-959-90) and Sterile Saline Tubes         (Remel, Catalog #064446) were used in the collection process.     -   Samples were collected by a single individual, the Study Nurse,         so as to remove variability due to operator error and to         maintain a single chain of custody of the samples.     -   Samples were collected at approximately the same time each day.     -   When sampling bedding or gowns after use by patients:         -   Bedding and gowns were collected from patients prior to             bathing;         -   Bedding and gowns were not collected from patients who had             been incontinent in the prior 20 hours;         -   If bedding or gowns had been used by patients who were             admitted with co-morbidities which included infectious             diseases, this fact was noted in the comments that accompany             the sample. The specific infectious disease(s) were noted in             the sample comments.         -   Swab samples were not taken from bedding or gowns that were             visibly stained or dirty.     -   The Study Nurse, using sanitized gloves, removed the bedding and         gowns to be swabbed from care facility, placing the items in a         sterile bag. The sterile bags were labeled indicating the Study         ID Number, collection date, and collection sites. Labels were         placed on the outside of the sterile bags.     -   Swab sampling was done in a room separate from patients' rooms,         on a table surface that had been sanitized. Swab sampling was         administered using a disposable 4 cm×5 cm rectangular template         allowing exposure of 20 cm² of fabric surface area. Templates         were used once and then disposed, to prevent cross         contamination.     -   After swabbing the bedding or gowns, each test swab was enclosed         in its own tube containing a sterile saline solution. The         description was written on each sample at the top of the sample         container. Labels indicating the Study ID Number, Patient's         Study ID No., collection date, collection site, and sample         details were used.     -   After swabbing, the bedding and gowns used in the testing were         placed in the soiled linen receptacle for laundering.     -   A laboratory chain-of-custody sheet was completed and placed         with the samples. A copy of this form was maintained by the         Study Nurse.     -   All samples and swabs were placed in a small zip-lock bag.         Bagged samples were then placed in a refrigerator until they         were shipped to the testing laboratory. In preparation for         shipping, dry ice or the equivalent was packed with the samples.         Samples were packed so that that they did not come into direct         contact with the dry ice. No ice melted onto the samples.     -   In preparation for shipment to the testing laboratory, a         Thermos® brand insulated container with the sample specimens,         was placed in a padded packing container and shipped via UPS         carrier. All samples were shipped to the testing laboratory to         arrive within twenty-four (24) hours of their collection.

Analysis of Swab Specimens for Bacteria by Culture on Agar Plates

All bacterial samples collected for this trial were analyzed by an independent laboratory, EMSL Inc., 1101 Aviation Parkway, Suite A, Morrisville, N.C., 27560; Phone: 919-465-3900, Fax: 919-465-3950.

Suspensions and dilutions were made from swab samples, incubated on trypticase soy agar with 5% sheep blood agar plates at 35±2° C. for 2 days, then at room temperature for 2 days. Any growth was identified by gram stain and biochemical testing as needed. The top three pathogens for each sample were identified and quantified in units of CFUs per square centimeter of pathogens for each item. These quantities were totaled and then divided by the number of items to get a total average of bioburden present.

Treated fabrics, according to embodiments of the present invention, are capable of allowing no more than a total average of about twenty-two (22) CFUs per square centimeter of the pathogens listed in Table 6 to be formed on a surface thereof.

TABLE 6 Descriptions of Pathogens Acidovorax delafieldii Acidovorax delafieldii is an aerobic, Gram-negative bacillus isolated from soil. There have not been any reports of human infections. Acinetobacter Acinetobacter baumannii is a species of pathogenic bacteria called aerobic Gram- baumannii negative bacillus and is naturally sensitive to relatively few antibiotics. Acinetobacter enters into the body through open wounds, catheters, and breathing tubes. It usually infects those with compromised immune systems, such as the wounded, the elderly, children or those with immune diseases. Colonization poses no threat to people who aren't already ill, but colonized health care workers and hospital visitors can carry the bacteria into neighboring wards and other medical facilities. Actinomycete Actinobacteria are a group of Gram-positive bacteria. They include some of the most common soil life, freshwater and marine life, playing an important role in decomposition of organic material. Bacillus cereus Bacillus cereus is an endemic, soil-dwelling, Gram-positive, rod-shaped bacterium. Some strains are harmful to humans and cause foodborne illness, while other strains can be beneficial as probiotics for animals. B. cereus bacteria are facultative anaerobes, and like other members of the genus Bacillus can produce protective endospores. B. cereus is responsible for a minority of foodborne illnesses (2-5%), causing severe nausea, vomiting and diarrhea. Bacillus circulans Bacillus circulans is a large aerobic, Gram-positive or Gram-variable bacillus that produces endospores. It is a thermotolerant bacterium, capable of growth at 122° F. It is isolated primarily from soil. Rarely associated with human infection. Bacillus licheniformis Bacillus licheniformis is a large aerobic, Gram-positive or Gram-variable bacillus that produces endospores. It is ubiquitous in nature being found in soil, dust, water, plants, humans and animals. Rarely associated with human infection. Bacillus sphaericus Bacillus sp. is a large aerobic Gram-positive or Gram-variable bacillus that produces endospores. Found in food, soil and water; rarely associated with food poisoning and infection. Brevundimonas Brevundimonas diminuta is an aerobic, oxidase-positive, Gram-negative bacillus. diminuta Found in water and hospital equipment; occasionally associated with human infection. Corynebacterium Corynebacterium is a genus of Gram-positive rod-shaped bacteria. They are widely coyleae distributed in nature and are mostly innocuous. Corynebacterium sp. See Corynebacterium coyleae. Enterococcus Enterococci are Gram-positive, catalase-negative, facultative anaerobes. Most casseliflavus human clinical isolates are due to either E faecalis (74-90%) or E faecium (5-16%). Occasionally, human infections can be due to Enterococcus raffinosus, Enterococcus casseliflavus, or Enterococcus durans. Enterococcus faecalis Enterococcus faecalis is a Gram-positive bacterium inhabiting the gastrointestinal tracts of humans and other mammals. A commensal organism like other species in the genus Enterococcus, E. faecalis can cause life-threatening infections in humans, especially in the nosocomial (hospital) environment, where the naturally high levels of antibiotic resistance found in E. faecalis contribute to its pathogenicity. Enterococcus Enterococcus gallinarum is a species of Enterococcus. Found in fowl. gallinarum Enterococcus sp. Enterococcus is a genus of lactic acid bacteria of the phylum Firmicutes. Enterococci are Gram-positive cocci that often occur in pairs or short chains and are difficult to distinguish from Streptococci on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: E. faecalis (90-95%) and E. faecium (5-10%). Gram positive bacillus See Bacillus cereus. Gram positive cocci Gram positive cocci are a common family of bacteria. Examples include Staphylococcus albus, which grows on the skin; Staphylococcus aureus, a frequent inhabitant of the skin, nasal passages, and the gastrointestinal tract; or Streptococcus mutans, a common inhabitant of the mouth. Streptococci cause “strep throat”, middle ear infections, scarlet fever, or rheumatic fever. Gram positive rod Many Gram-positive cocci are commensal organisms that cause infection only when they find their way into normally sterile areas. They are the most common cause of skin infections and a frequent cause of pneumonia and septicemia. Although generally susceptible to a broad range of antibiotics, certain strains have developed resistance to every available antimicrobial agent. Klebsiella sp. Klebsiella is a genus of Gram-negative, rod-shaped bacteria. Frequent human pathogens, Klebsiella organisms can lead to a wide range of disease states, notably pneumonia, urinary tract infections, septicemia, ankylosing spondylitis, and soft tissue infections. Lactococcus lactis Lactococcus lactis is a Gram-positive bacteria used extensively in the production of buttermilk and cheese. The capability to produce lactic acid is one of the reasons why Lactococcus lactis is one of the most important micro-organisms involved in the dairy industry. It has been considered as an opportunistic pathogen, even though, the number of clinical cases associated with infections by these microorganisms has increased in the last decade in both humans and animals. Microbacterium Microbacterium is a Gram-positive soil organism. aurantiacum Micrococcus luteus Micrococcus luteus is a Gram positive, spherical, saprotrophic bacterium that belongs to the family Micrococcaceae. M. luteus is found in soil, dust, water and air, and as part of the normal flora of the mammalian skin. The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. Although M. luteus is non-pathogenic and usually regarded as a contaminant, it should be considered as an emerging nosocomial pathogen in immunocompromised patients. Micrococcus sp. See description for Micrococcus luteus. Micrococcus lylae Micrococcus lylae is an aerobic, Gram-positive coccus occurring in tetrads (groups of four). The primary habitat is mammalian skin. The majority of strains are nonpathogenic, but some strains may occasionally be opportunist pathogens. Nocardia farcinica A species of Nocardia that sometimes causes systemic nocardiosis. Nocardiosis is a serious infection caused by a fungus-like bacterium that begins in the lungs and can spread to the brain. The incubation period is not known, but is probably several weeks. The bacteria can enter the human body when a person inhales contaminated dust. Less often, people can pick up the bacteria in contaminated puncture wounds or cuts. Pseudomonas putida Pseudomonas putida is a rod-shaped, flagellated, Gram-negative bacterium that is found in most soil and water habitats where there is oxygen. Pseudomonas species are opportunistic pathogens that primarily cause nosocomial infections. Pseudomonas aeruginosa is the most important pseudomonad species, but other species, including Pseudomonas putida, have been associated with clinical infections, particularly among children. Pseudomonas Pseudomonas oryzihabtans is a Gram-negative, rod-shaped, motile bacterium that oryzihabitans can cause peritonitis, septicemia, endophthalmitis, and bacteremia. Rhizobium radiobacter Rhizobium radiobacter is an aerobic, Gram-negative bacterium closely related to several species of plant pathogens that occur in soils worldwide. It has been associated with human systemic diseases, including peritonitis, urinary tract infection, cellulitis, and myositis. It has also been associated with central venous catheter-associated bloodstream infections. Staphylococcus aureus Staphylococcus aureus is an aerobic Gram-positive coccus. It can be part of the normal flora of the skin, skin glands, anterior nares, mucous membranes, gastrointestinal tract, and genital tract of humans, warm-blooded animals, and birds. It is an opportunistic pathogen causing a wide range of infections including: furuncles (boils), carbuncles, impetigo, epidermal necrolysis, osteomyelitis, meningitis, endocarditis, pneumonia, mastitis, bacteremia, enterocolitis, staphylococcal food poisoning and toxic shock syndrome. Staphylococcus cohnii Staphylooccus cohnii is an aerobic Gram-positive coccus. It is part of the normal flora of the skin, skin glands, anterior nares, and mucous membranes of humans and animals especially primates. Rarely an opportunistic pathogen for humans, S. cohnii can cause urinary tract infections, wound infections, endocarditis, and septicemia. Staphylococcus Staphylococcus epidermidis is an aerobic Gram-positive coccus. It is part of the epidermidis normal flora of the skin, skin glands, anterior nares, and mucous membranes of humans and animals. S. epidermidis is an opportunistic pathogen for humans that can cause urinary tract infections, wound infections, endocarditis, and septicemia. Staphylococcus Staphylococcus haemolyticus is a species of bacterium belonging to the genus haemolyticus Staphylococcus. It is a Gram positive coccus, coagulase negative, and catalase positive. Frequently found as a commensal organism on humans and animals, S. haemolyticus occurs infrequently as a cause of soft-tissue infections, usually in immunocompromised patients. Staphylococcus Staphylococcus hominis is an aerobic Gram-positive coccus. It is part of the normal hominis flora of the skin, skin glands, anterior nares, and mucous membranes of humans. It is an opportunistic pathogen for humans causing conjunctivitis, urinary tract infections, wound infections, and septicemia. Staphylococcus See Staphylococcus epidermidis. pasteuri Staphylococcus sp. Indeterminate non-aureus staphylococcus organism. (non-aureus) Staphylococcus Staphylococcus xylosus is an aerobic Gram-positive coccus. It may be part of the xylosus normal flora of the skin of humans and primates. May be associated with urinary tract infection.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein. 

1. A method of reducing bioburden within a medical facility, comprising: (a) fitting essentially all beds within the facility with clean sheets, wherein each sheet comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; then (b) occupying the beds with patients, wherein the sheets on average contain no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a bed occupant; and (c) repeating steps (a)-(b) for a number of times sufficient to reduce the bioburden within the facility.
 2. The method of claim 1, wherein the warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier, one of the warp or filling yarns being 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric, and the other of the warp or filling yarns being continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric.
 3. The method of claim 1, wherein the pathogens are selected from the group consisting of gram negative and gram positive bacterial pathogens.
 4. The method of claim 2, wherein the warp yarns are 100% nylon and the filling yarns are 100% polyester.
 5. The method of claim 1, wherein an antimicrobial substance is topically applied to the fabric.
 6. The method of claim 2, wherein the warp yarn is a 70 denier, 48 filament, textured, continuous filament nylon yarn, and wherein the filling yarn is a 75 denier, 36 filament, continuous filament textured polyester yarn.
 7. The method of claim 2, wherein the non-round filament cross sections are star shaped cross sections or clover leaf cross sections.
 8. The method of claim 2, wherein the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels.
 9. The method of claim 1, wherein the fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.
 10. A method of reducing bioburden within a medical facility, comprising: (a) dressing each patient within the facility with a clean hospital gown, wherein each hospital gown comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; (b) maintaining the patients within beds in the facility, wherein the gowns on average contain no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a patient; and (c) repeating steps (a)-(b) for a number of times sufficient to reduce the bioburden within the facility.
 11. The method of claim 10, wherein the warp and filling yarns are about 30 denier to 200 denier, and are continuous filament polyester having round filament cross sections.
 12. The method of claim 10, wherein the pathogens are selected from the group consisting of gram negative and gram positive bacterial pathogens.
 13. The method of claim 11, wherein the warp and filling yarns are 100% polyester.
 14. The method of claim 10, wherein an antimicrobial substance is topically applied to the fabric.
 15. The method of claim 11, wherein the warp and filling yarns are 70 denier, 200 filament, textured, continuous filament polyester yarn.
 16. The method of claim 10, wherein the fabric has an average Kawabata geometric roughness of less than about 1.2 microns and a percent (%) dryness after 1 hour of 100%.
 17. A method of reducing bioburden within a medical facility, comprising: fitting essentially all beds within the facility with clean sheets, wherein each sheet comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; collecting the sheets after twenty (20) hours of use by occupants of the beds; and laundering the collected sheets; wherein a surface of each sheet allows no more than a total average of about twenty-five (25) CFUs of pathogens per square centimeter to be formed thereon after at least thirty (30) laundering cycles.
 18. The method of claim 17, wherein the warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier, one of the warp or filling yarns being 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric, and the other of the warp or filling yarns being continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric.
 19. The method of claim 17, wherein the pathogens are selected from the group consisting of gram negative and gram positive bacterial pathogens.
 20. The method of claim 18, wherein the warp yarns are 100% nylon and the filling yarns are 100% polyester.
 21. The method of claim 17, wherein an antimicrobial substance is topically applied to the fabric.
 22. The method of claim 18, wherein the warp yarn is a 70 denier, 48 filament, textured, continuous filament nylon yarn, and wherein the filling yarn is a 75 denier, 36 filament, continuous filament textured polyester yarn.
 23. The method of claim 18, wherein the non-round filament cross sections are star shaped cross sections or clover leaf cross sections.
 24. The method of claim 18, wherein the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels.
 25. The method of claim 17, wherein the fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.
 26. A method of reducing bioburden within a medical facility, comprising: (a) fitting essentially all beds within the facility with clean sheets, wherein each sheet comprises a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, and wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; then (b) occupying the beds with patients, wherein the sheets on average contain no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a bed occupant; (c) dressing each patient within the facility with a clean hospital gown, wherein each hospital gown comprises the woven fabric; then (d) maintaining the patients within beds in the facility, wherein the gowns on average contain no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter after twenty (20) hours of use by a patient; and (e) repeating steps (a)-(d) for a number of times sufficient to reduce the bioburden within the facility.
 27. The method of claim 26, wherein the warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier, one of the warp or filling yarns being 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric, and the other of the warp or filling yarns being continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric.
 28. The method of claim 26, wherein the pathogens are selected from the group consisting of gram negative and gram positive bacterial pathogens.
 29. The method of claim 27, wherein the warp yarns are 100% nylon and the filling yarns are 100% polyester.
 30. The method of claim 27, wherein an antimicrobial substance is topically applied to the fabric.
 31. The method of claim 27, wherein the warp yarn is a 70 denier, 48 filament, textured, continuous filament nylon yarn, and wherein the filling yarn is a 75 denier, 36 filament, continuous filament textured polyester yarn.
 32. The method of claim 27, wherein the non-round filament cross sections are star shaped cross sections or clover leaf cross sections.
 33. The method of claim 27, wherein the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels.
 34. The method of claim 26, wherein the fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.
 35. A bioburden reducing fabric, comprising: a woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof; wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings; and wherein a surface of the fabric, when exposed to a pathogenic environment for twenty (20) hours, allows no more than a total average of about twenty-two (22) CFUs of pathogens per square centimeter to be formed thereon.
 36. The fabric of claim 35, wherein the warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier, one of the warp or filling yarns being 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric, and the other of the warp or filling yarns being continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric.
 37. The fabric of claim 35, wherein the pathogens are selected from the group consisting of gram negative and gram positive bacterial pathogens.
 38. The fabric of claim 36, wherein the warp yarns are 100% nylon and the filling yarns are 100% polyester.
 39. The fabric of claim 35, wherein an antimicrobial substance is topically applied to the fabric.
 40. The fabric of claim 36, wherein the warp yarn is a 70 denier, 48 filament, textured, continuous filament nylon yarn, and wherein the filling yarn is a 75 denier, 36 filament, continuous filament textured polyester yarn.
 41. The fabric of claim 36, wherein the non-round filament cross sections are star shaped cross sections or clover leaf cross sections.
 42. The fabric of claim 36, wherein the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels.
 43. The fabric of claim 35, wherein the fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.
 44. A fabric, comprising: a non-treated woven fabric having warp yarns and filling yarns woven together in a plain weave to provide a pill resistant fabric having identical surfaces on both sides thereof, wherein the warp yarns are about 30 denier to 100 denier, and the filling yarns are about 30 denier to 100 denier, one of the warp or filling yarns being 100% continuous filament nylon having round filament cross sections and making up at least 40% by weight of the fabric, and the other of the warp or filling yarns being continuous filament polyester having non-round filament cross sections or nylon having non-round filament cross sections and making up the remainder of the weight of the fabric.
 45. The fabric of claim 44, wherein the warp yarns are 100% nylon and the filling yarns are 100% polyester.
 46. The fabric of claim 44, wherein the filling yarns are 100% nylon.
 47. The fabric of claim 44, wherein the warp yarn is a 70 denier, 48 filament, textured, continuous filament nylon yarn, and wherein the filling yarn is a 75 denier, 36 filament, continuous filament textured polyester yarn.
 48. The fabric of claim 44, wherein the non-round filament cross sections are star shaped cross sections or clover leaf cross sections.
 49. The fabric of claim 44, wherein the continuous filament warp or filling yarns with non-round filament cross sections are configured such that adjacent filaments form wicking channels.
 50. The fabric of claim 44, wherein the fabric has an average Kawabata geometric roughness of less than about 1.7 microns and a percent (%) dryness after 1 hour of 100%.
 51. The fabric of claim 44, wherein the fabric has zero percent (0%) weight loss after one hundred (100) launderings in accordance with the AATCC 61 test method.
 52. Use of the fabric of claim 35 in the manufacture of bed sheets for reducing bioburden within a medical facility.
 53. Use of the fabric of claim 35 in the manufacture of bed sheets for reducing bioburden within a medical facility, wherein the bioburden is reduced by at least half (e.g., 50%) on beds in the medical facility occupied by human patients when the sheets are changed at least every two days (e.g., 24-48 hours).
 54. Use of the fabric of claim 35 in the manufacture of bed sheets for reducing bioburden within a medical facility maintained at a temperature of between about 60° F. (15° C.) and 80° F. (27° C.) and at a humidity level of between about 35% relative humidity and about 55% relative humidity, wherein the bioburden is reduced by at least half (e.g., 50%) on beds in the medical facility occupied by human patients when the sheets are changed at least every two days (e.g., 24-48 hours).
 55. Use of the fabric of claim 35 in the manufacture of hospital gowns for reducing bioburden within a medical facility.
 56. Use of the fabric of claim 44 in the manufacture of bed sheets for reducing bioburden within a medical facility.
 57. Use of the fabric of claim 44 in the manufacture of bed sheets for reducing bioburden within a medical facility, wherein the bioburden is reduced by at least half (e.g., 50%) on beds in the medical facility occupied by human patients when the sheets are changed at least every two days (e.g., 24-48 hours).
 58. Use of the fabric of claim 44 in the manufacture of bed sheets for reducing bioburden within a medical facility maintained at a temperature of between about 60° F. (15° C.) and 80° F. (27° C.) and at a humidity level of between about 35% relative humidity and about 55% relative humidity, wherein the bioburden is reduced by at least half (e.g., 50%) on beds in the medical facility occupied by human patients when the sheets are changed at least every two days (e.g., 24-48 hours).
 59. Use of the fabric of claim 44 in the manufacture of hospital gowns for reducing bioburden within a medical facility. 